Quote:
Originally Posted by 66sprint6
We're trying to sell our Round Port engine that we bought a while ago. Of course, the first question that prospective buyers are asking is how much HP. We don't know what cam is in it, but here are the other specs:
SRP pistions, 4.155 with a 7cc valve notch
Eagle crank, 4.25 sroke
Edelbrock 72cc heads
Assuming nominal .004 deck height and a .039 compressed gasket thickness
I went on Butler's site, used their CR calculator and found the engine to have an astounding 11.67:1 CR with this combo. Any guess on what kind of horsepower/tq this thing makes? We're trying to figure out what to do with it. The CR numbers are scaring some people away.
|
I plugged in your numbers on the Wallace Racing calculator assuming a 4.3” head gasket bore and came up with 11.59:1 compression. So pretty close to the Butler calculator.
Then keeping everything the same except for using 75ccs for the heads instead of 72cc you end up with 11.25:1. The 72cc Edelbrock heads I’ve seen reported here on the forums are commonly at 75 and not the advertised 72ccs.
So 11.25:1 is a little more in line with what you can get away with on pump premium, 93 octane preferably. Hopefully it has enough cam to go along with the higher compression.